Aquatic Plant Forum banner

Will spiral screw-in CFLs work?

11721 Views 11 Replies 8 Participants Last post by  jburn
I have a 20" high tank and I am currently using three 27W spiral screw-in compact fluorescent bulbs to light the tank. I know that these spiral bulbs lose strength due to the restrike. What kind of plants do you guys think I can grow with this lighting?

1 - 2 of 12 Posts



so yes you can, getting the right color spectrum (around 6500+k) is important though to help ward off algae.
What size is the tank in gallons? at 20" high the spiral bulbs won't be very effective near the bottom so high-light groundcovers like hc are probably out, but you should be able to grow a variety of plants under that lighting.
See less See more
Couple of things, "restrike" is indeed the amount of time it takes a bulb to relight once extinguished. However, many people in the fishkeeping world also use it as a term to describe the light that is lost due to being reflected back into the bulb it originated from, so you're both right. ;)

With a spiral CFL you lose approximately 1/3 of the wattage to this type of restrike.

with 3 bulbs at 27w each you have a total wattage of 81. Minus (about) 1/3 for the restrike issue you end up with 54 effective watts.

54 watts over a 20 gallon tank works out to 2.7 WPG. Fairly high light, if you are not running at least DIY co2 you will have constant algae, I would be willing to wager you would have just fine growth if you completely remove one bulb and just run with two. And co2 or flourish for sure.

Either way, you definitely want to get rid of the 2700k bulb, it is not helping anything but the green water.
1 - 2 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.